Symposium on the ICJ Climate Change Advisory Opinion: What’s Next? A Proposal for a UN General Assembly Special Session on Climate Change

[David W. Patterson is a PhD candidate at the Groningen Centre for Health Law, Faculty of Law, University of Groningen, and a coordinator of the Human Rights and the Climate Crisis Working Group of the Netherlands Network for Human Rights Research. 

Benjamin Mason Meier is a Professor of global health policy at the University of North Carolina at Chapel Hill and a Senior Scholar at the O’Neill Institute for National and Global Health Law.]

The International Court of Justice (ICJ) delivered its advisory opinion on climate change on 23 July 2025, holding that States are obligated to limit climate change and are responsible for climate damages. This ICJ advisory opinion offered crucial interpretations of human rights obligations in the climate crisis. How can States now leverage the ICJ’s guidance to meet their obligations regarding climate change mitigation, adaptation, and loss & damage? 

With a Climate Summit on the agenda for the UN General Assembly (UNGA) session in September 2025, this blog post argues that States should draw from the ICJ advisory opinion to call for a UN General Assembly Special Session (UNGASS) on Climate Change. This UNGASS could provide an opportunity to debate and adopt a ‘Declaration of Commitment to Climate Action’ – with human rights-based commitments that complement, not duplicate, obligations under the UN Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the Paris Agreement (‘the climate treaties’). Facilitating accountability for State action, the Declaration should also request the UN Secretary-General to report periodically to the UNGA on States’ progress in achieving the commitments in the Declaration. 

Climate Change Before International Courts and Tribunals

In March 2023, the UN General Assembly requested that the ICJ issue an advisory opinion on international legal obligations, including human rights obligations, to protect vulnerable populations and future generations from the adverse effects of climate change. Drawing from wide-ranging testimony by national governments and intergovernmental organizations, the ICJ advisory opinion (para. 172) held that States’ obligations to address climate change are governed by a wide range of applicable laws, including certain environmental treaties, core human rights treaties, and customary international law.

This ICJ advisory opinion is in line with the evolving consensus of the UN General Assembly and the UN human rights system. Other international courts and tribunals and adjudicating bodies such as the Inter-American Court of Human Rights and the European Court of Human Rights, as well as the UN Human Rights Council, Office of the UN High Commissioner for Human Rights, and the UN Special Rapporteurs on the human right to a healthy environment and on human rights and climate change have all provided extensive guidance on human rights-based approaches to climate change. 

Applying these rights in April 2024, the European Court of Human Rights, recognizing the right to health of older women, held in KlimaSeniorinnen and Others v Switzerland [para 573] that the Swiss authorities had not acted in a timely and appropriate way to devise, develop, and implement relevant legislation and measures to address climate change. In May 2024, an advisory opinion [para 66] issued by the International Tribunal for the Law of the Sea (ITLOS) similarly noted that climate change represents an existential threat and raises human rights concerns. Drawing from these previous decisions in July 2025, the Inter-American Court of Human Rights delivered an advisory opinion [part VII (1)] declaring that the climate crisis is a human rights emergency. 

A UN General Assembly Special Session (UNGASS) on Climate Change

The ICJ advisory opinion, affirming international legal guidance across the global governance system, must now be supported by political commitments in the UN General Assembly. The General Assembly has already begun to engage with the human rights implications of climate change, recognizing in 2022 the right to a clean, healthy and sustainable environment and affirming the importance of the environment to the enjoyment of all human rights. Building from this engagement at its 80th session in September 2025, the General Assembly will have a unique opportunity to request that the UN Secretary-General convene an UNGASS to debate the climate crisis, the advisory opinion from the ICJ and decisions of other global and regional courts and tribunals, the human rights implications of climate injustice, and the inadequate progress in achieving the Paris Agreement goals. 

In this context, the UN General Assembly is authorized to hold high-level Special Sessions to address urgent, wide-ranging concerns, as seen in previous special sessions on corruption, COVID-19, drugs, children, and the HIV pandemic. An UNGASS may be convened by the UN Secretary-General at the request of the UN Security Council or a majority of UN Member States (UN Charter: art. 20). Voting at the UNFCCC and Paris Agreement Conferences of Parties (CoPs) requires a consensus, and motions can be blocked by a single country. This limitation has long stalled progress at the CoPs. However, the General Assembly only requires a simple majority to adopt a decision to convene a Special Session. Given that the General Assembly request for an ICJ advisory opinion in 2023 was sponsored by more than 130 States and adopted without a vote, it is likely that the simple majority needed to request an UNGASS on Climate Change could easily be obtained.

Commitments to Human Rights-based Climate Action to Complement the Climate Treaties

This proposed UNGASS on Climate Change should reflect the ICJ’s guidance, address the human rights implications of climate injustice, and aim to complement, not duplicate, obligations and processes under the UNFCCC, the Kyoto Protocol, and the Paris Agreement. The climate treaties focus on inter-state processes: the Paris Agreement goals, national political commitments expressed in States’ Nationally Determined Contributions, and periodic reporting of progress and replanning. By contrast, the international human rights treaties and related customary international law also set out States’ obligations to respect, protect, and fulfil the human rights of their citizens and other persons within their jurisdictions. The ICJ advisory opinion has clarified that States have obligations to respond to the climate crisis under both the climate and human rights legal regimes [paras 369-404]. 

The UNFCCC Secretariat has already published guidance that reflects, to a limited extent, States’ human rights obligations. These include the Enhanced Transparency Framework, which requests Member Parties to report on institutional arrangements and governance, including for ‘consultation and participation.’ In preparation for States’ updated nationally determined commitments, due in 2025, the UNFCCC Secretariat has also developed guidance on ‘inclusive engagement’ for specific groups, including people in vulnerable situations, children and youth, women and girls, persons with disabilities, Indigenous Peoples, and local communities. Yet, while the Paris Agreement references human rights, including the right to health, in its Preamble, the UNFCCC Secretariat guidance does not reference applicable international human rights law, and there is no periodic monitoring of States’ application of this UNFCCC Secretariat guidance. 

With the ICJ advisory opinion looking beyond the UNFCCC to address obligations under international human rights law, the UNGASS should also look to the Office of the UN High Commissioner for Human Rights (OHCHR), which has provided explicit human rights-based guidance on integrating human rights at the core of the UNFCCC and on integrating human rights into NDCs. As noted, there is as yet no periodic monitoring process to assess how States have implemented this guidance in, for example, participatory planning, mainstreaming gender, and the perspectives of Indigenous Peoples. Such monitoring mechanisms will be crucial to facilitate accountability for the realization of human rights in the climate change response.

An Accountability Framework for Human Rights-based Climate Action

An UNGASS on climate change could develop a policy framework to implement the procedural and substantive obligations identified by the ICJ and other entities noted above, concluding with a Political Declaration that reaffirms human rights obligations for a healthy environment and establishes an accountability framework to periodically monitor States’ actions to meet their obligations. 

In facilitating this accountability, there is a useful precedent in the global HIV/AIDS response for rigorous reporting and monitoring of UNGASS commitments, which could be adopted at the UNGASS on climate change. In this earlier context in 2001, the UNGASS on HIV/AIDS adopted the Declaration of Commitment on HIV/AIDS. This Declaration reflected States’ human rights obligations to address the HIV pandemic and, critically, called for periodic reports from the UN Secretary-General on States’ progress in achieving their commitments in the Declaration. 

To establish this monitoring mechanism following the UNGASS on HIV/AIDS, UNAIDS developed a comprehensive monitoring tool to assess States’ progress, which includes the formal participation of civil society in the monitoring process. The monitoring tool incorporates the ‘National Commitments and Policy Instrument’ (NCPI), with questions on related policies, strategies, and laws. UNAIDS publishes the Global AIDS Update annually, reflecting States’ progress in implementing their commitments on HIV/AIDS. This monitoring of State implementation of their HIV/AIDS commitments, which continues today, has been critical to maintaining policy momentum and facilitating State accountability following the UNGASS.

Conclusion

The ICJ advisory opinion provides a springboard for States and civil society to galvanize the UNGA in September 2025 to call for a UNGASS on climate change. By focusing on the human rights dimensions of the climate crisis, including States’ obligations to their citizens, other people within their jurisdictions, and international responsibility for transboundary harm, this UNGASS would be crucial to advancing human rights in the climate response. Critically, the ensuing Declaration of Commitment to Climate Action should request the UN Secretary-General to report periodically to the UNGA on States’ progress in achieving the commitments in the Declaration. 

This UNGASS on Climate Change will require urgent UNGA action to maintain the momentum coming out of the ICJ. In 2017, environmentalist Bill McKibben noted that:

Winning slowly is the same as losing. If we don’t win very quickly on climate change, then we will never win. That’s the core truth about global warming. It’s what makes it different from every other problem our political systems have faced.

The ICJ has seized the imperative to advance State obligations in the climate crisis. The UNGA must now carry these obligations forward to ensure that States meet their commitments to urgent, effective, human rights-based climate action as soon as possible.